JP2000200055A - Magneto phoretic display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic panel capable of recovering a mark of partial erasure of display to an color tone equivalent to that of non-display part without stains left on the mark. SOLUTION: In this magneto phoretic display panel building in a dispersion liquid in which magnetic particles are dispersed in a colored dispersion medium, the dispersion medium consists of two kinds of dispersion media of a 1st dispersion medium and a 2nd dispersion medium, and the 1st dispersion medium and the 2nd dispersion medium have substantially same specific gravity, and the 1st dispersion medium is a colored one with a hiding power and forms a 1st layer which has a stronger affinity for the inside of a screen side of the above- mentioned panel than the 2nd dispersion medium and is arranged on the screen side of the panel, and the 2nd dispersion medium is not substantially mixed with the 1st dispersion medium but forms a 2nd layer arranged on the back side of the panel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetophoretic display panel for partially erasing a display on a display surface.

[0002]

2. Description of the Related Art Conventionally, a magnetophoretic display panel (hereinafter, referred to as a "magnetic panel") that performs display using the magnetophoresis of magnetic particles.
A magnetic panel is known in which a large number of cells are provided between a transparent display surface substrate and a rear substrate, and a dispersion liquid in which magnetic particles are dispersed in a coloring dispersion medium is sealed in the cells. Also known is a magnetic panel in which a colored dispersion medium formed by dispersing magnetic particles in a transparent microcapsule shell is enclosed, and a number of such microcapsule shells are provided between a transparent display surface substrate and a back substrate. I have.

In order to erase the display on the display surface of the magnetic panel described above, a method can be considered in which a magnetic field is applied to the colored dispersion medium from the back side by an erasing magnet to collect and erase the magnetic particles at the display location on the back side. In the display erasing method in which the erasing magnet is scanned, it is easy to erase the entire display at once, but partial erasing of the display is not easy because the apparatus is complicated.

Therefore, as an erasing device capable of partially erasing a display, a movable magnetic body is provided on a display surface of a magnetic panel in which magnetic particles are dispersed in a coloring dispersion medium, and the movable magnetic material is provided on the back surface of the magnetic panel. Being sucked into the body and following its movement,
There has been proposed a magnetic panel erasing apparatus provided with an erasing magnet (electromagnet or permanent magnet) for applying a magnetic field to the dispersion liquid (JP-B-57-46439). Further, as an improved type of the partial erasing, a movable magnetic body provided on a display surface of a magnetic panel is provided with a erasing electromagnet provided on a back surface of the magnetic panel by a mechanical device so as to follow the movement of the movable magnetic body. A magnetic panel erasing device has been proposed in which the movable magnetic body is electrically connected to the erasing electromagnet to apply a magnetic field to the dispersion liquid only when the movable magnetic body scans a display erasing portion. (Japanese Utility Model Publication No. 3-27823).

[0005] All of the conventional partial erasing devices for magnetic panels employ an erasing method in which a magnetic field is applied to the dispersion liquid from the back surface of the magnetic panel. This is a method in which an erasing magnet disposed on the back surface of a magnetic panel is driven to move, and a complicated driven mechanism is required, and the problem of a complicated structure has not been solved.

Accordingly, the present inventors have solved the above-mentioned problems of the conventional partial erasing apparatus and have developed a display partial erasing technique for a magnetic panel which can smoothly and partially erase a display with an easy and simple mechanism. (Japanese Patent Application No. 10-119151). According to this prior invention, an erasing magnet is arranged on a display surface of a magnetic panel containing a dispersion liquid in which magnetic particles are dispersed in a coloring dispersion medium, and a writing from the display surface of the magnetic panel is provided on the back surface of the magnetic panel. The ferromagnetic material which is not affected by the writing action is substantially fixed to the entire surface of the magnetic particles by the scanning of the magnet, and the magnetic particles are aggregated by magnetizing the ferromagnetic material by magnetic induction by the scanning of the erasing magnet. It is characterized in that a magnetic field to be dispersed is applied without causing the dispersion.

An example of partial erasure according to the prior invention is conceptually described as shown in FIGS. FIG. 9 is a diagram relating to display formation, and FIG. 10 is a diagram relating to partial erasure. 9 and 10, a large number of cells 4 are formed by fixing a large number of cell constituent members 3 between a display surface substrate 1 and a back surface substrate 2, and a dispersion liquid in which magnetic particles 5 are dispersed in the cells 4. The magnetic medium A is formed by enclosing a dispersion medium 12 as a magnetic medium A, and a ferromagnetic plate 10 is arranged and fixed on the back surface of the magnetic panel A. The ferromagnetic plate 10 covers substantially the entire back surface of the magnetic panel A. Further, an erasing magnet 14 to which a spacer 13 is fixed is movably provided on the display surface of the magnetic panel A.

The display of the magnetic panel A is performed by moving the magnetic pen 11 provided with the writing magnet 17 in the direction of the arrow A along the surface of the display surface substrate 1 to apply a magnetic field to the dispersion medium 12, and The magnetic particles 5 are adsorbed inside 1, and the adsorbed portions generate contrast with other portions of the dispersion liquid 12, thereby forming a display. Partial erasure of the formed display is
The erasing magnet 14 to which the spacer 13 is fixed is moved along the surface of the display surface substrate 1 in the direction of the arrow B to the display portion to be erased, and a magnetic field is applied to this display portion. as a result,
The ferromagnetic plate 10 is magnetically induced and magnetized by the erasing magnet 14, and the magnetic particles 5 of the display portion to be erased are arranged in the direction of the magnetic field generated between the erasing magnet 14 and the ferromagnetic plate 10. Apparently, the display part disappears.

According to the prior invention, the movable magnetic member disposed on the display surface of the magnetic panel does not require a complicated driven mechanism for driving the erasing magnet disposed on the back surface of the magnetic panel on the magnetic panel display surface. This is excellent in that a simple mechanism in which the provided erasing magnet is combined with a ferromagnetic plate provided substantially over the entire rear surface of the magnetic panel can easily and smoothly erase the partial display. However, when the partial erasure according to the prior invention is applied, there is a problem that a trace of partially erasing the display remains, and the color tone equivalent to the color tone of the dispersion medium in the non-display portion without display from the beginning cannot be recovered. There was found.

In addition, apart from the problem that the partial erasure marks remain in the magnetic panel of the present invention, it has also been found that the contrast of the dispersed liquid between the display portion and the non-display portion is not yet sufficient. This is a problem related to the shielding power of the colored dispersion medium. When a colored dispersion medium having a weak shielding power is used, the magnetic particles of the non-display portion adsorbed on the back side of the magnetic panel can be seen through to some extent and sufficiently. Therefore, the contrast of the dispersion liquid between the display unit and the non-display unit is weakened. On the other hand, when a colored dispersion medium having a strong shielding power is used, the magnetic particles of the non-display portion adsorbed on the back side of the magnetic panel are sufficiently shielded, but the magnetic particles adsorbed on the display surface side are inevitably small in amount. However, a colored dispersion medium is interposed between the inside of the display surface and the magnetic particles, and the magnetic particles adsorbed on the display surface side are appropriately shielded by the strong shielding power of the interposed colored dispersion medium, and eventually the display unit and the non-display are not displayed. The contrast of the dispersed liquid in the part is weakened.

[0011]

SUMMARY OF THE INVENTION An object of the present invention relates to an improvement of the prior invention. Even if partial erasure of a display is performed, no stain remains on the erasure of the partial display, and the trace is removed. It is an object of the present invention to provide a magnetic panel capable of recovering a color tone equivalent to the color tone of the non-display portion, and further to provide a magnetic panel capable of further increasing the contrast of the liquid dispersion between the display portion and the non-display portion.

[0012]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, have achieved a partial elimination and shielding structure of magnetic particles by using a two-layered dispersion medium incorporated in a magnetic panel. As a result, the present inventors have found that the above object can be achieved, and completed the present invention.

That is, a magnetic panel according to the present invention comprises a first dispersion medium and a second dispersion medium which are substantially not mixed as a dispersion medium, and the first dispersion medium is a second dispersion medium. Formed in a thinner layer than the dispersion medium, the first dispersion medium is disposed on the display surface side of the magnetophoretic display panel to form a shielding layer, and the second dispersion medium is disposed on a side other than the display surface side of the magnetophoretic display panel. The magnetic particles are arranged and dispersed.

A magnetic panel according to a second aspect is characterized in that the first dispersion medium and the second dispersion medium have substantially the same specific gravity.

According to a third aspect of the present invention, in the magnetic panel, the first dispersion medium is colored with a shielding property, or the second dispersion medium and the first dispersion medium are colored in different colors. It is characterized by.

The magnetic panel according to a fifth aspect is characterized in that the magnetic particles have an affinity for the second dispersion medium or have been subjected to a surface treatment having an affinity for the second dispersion medium. The magnetic panel according to claim 6, wherein the first dispersion medium has a stronger affinity for the display surface side of the magnetophoretic display panel than the second dispersion medium. The magnetic panel described above is characterized in that the second dispersion medium has a stronger affinity than the first dispersion medium except for the display surface side of the magnetophoretic display panel.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The magnetic panel can be constructed in accordance with the magnetic panel of the present invention, except that the colored dispersion medium of the dispersion liquid of magnetic particles has a constant two-layer structure. In the example of FIG. 1, the display surface substrate 1 and the back surface substrate 2
A large number of cells 4 are formed by adhering a large number of cell constituent members 3 to each other, and the magnetic particles 5, the first dispersion medium 6, and the second Dispersion medium 7
And the first dispersion medium 6 forms a first layer disposed on the display surface side of the magnetic panel without substantially mixing the first dispersion medium 6 and the second dispersion medium 7. Thus, the second dispersion medium 7 forms a second layer disposed on the back side of the magnetic panel. FIG. 1 shows a state in which the magnetic particles 5 are adsorbed on the back side of the magnetic panel.

In the example of FIG. 2, a dispersion layer of a large number of microcapsules 8 is provided between the display surface substrate 1 and the back substrate 2, and in the microcapsules 8, a transparent microcapsule shell 9 is provided. Inside, the magnetic particles 5, the first dispersion medium 6, and the second dispersion medium 7 for dispersing the magnetic particles 5
And the first dispersion medium 6 is disposed on the display surface side of the magnetic panel, that is, on the shell 9 side of the microcapsule, without the first dispersion medium 6 and the second dispersion medium 7 being substantially mixed. The first layer is formed, and the second dispersion medium 7 forms a second layer disposed outside the surface of the magnetic panel, that is, on the center side of the microcapsule 8.

In order to form the two-layer structure, in FIG. 1, a dispersion medium which is not compatible with each other and which is incompatible with each other may be selected as the first dispersion medium 6 and the second dispersion medium 7, and is preferably substantially the same. Have the same specific gravity. At the time of layer fixing, it can be achieved by making at least the inner surface of the display surface substrate 1 have a stronger affinity for the first dispersion medium 6 than for the second dispersion medium 7. As a method for making the inner surface of the display surface substrate 1 have a strong affinity for the first dispersion medium 6, for example, the first dispersion medium 6 is water,
When the second dispersion medium 7 is a hydrocarbon solvent that is incompatible with water, the display surface substrate 1 may be made of a hydrophilic material, or the inner surface of the display surface substrate 1 may be hydrophilized. .

In order to make the specific gravity of the first and second dispersion media substantially the same, the specific gravity can be adjusted by dissolving an additive or the like in one or both of the first and second dispersion media. . For example, there is a case where calcium bromide is dissolved in water to increase the specific gravity and make the specific gravity equal to that of the other dispersion medium.

Examples of the hydrophilic material constituting the display surface substrate 1 include polyvinyl alcohol and the like, and examples of the hydrophilic treatment of the inner surface of the display surface substrate include plasma treatment and ultraviolet irradiation. Conversely, when the first dispersion medium 6 is a hydrocarbon solvent having no compatibility with water and the second dispersion medium 7 is water, the display surface substrate 1 is made of a lipophilic material, or A method of subjecting the inner surface of the surface substrate 1 to lipophilic treatment may be used.

In FIG. 2, a material having a strong affinity for the first dispersion medium 6 can be selected as the material of the shell 9 of the microcapsule 8.

Generally, as a dispersion medium of the magnetic particles, a polar dispersion medium such as water, various alcohols and various glycols,
Organic solvents such as aliphatic hydrocarbons such as isoparaffin, aromatic hydrocarbons such as toluene and xylene, nonpolar dispersion media such as oils, glycerin, carbon tetrachloride, and kerosene are used. Within the range of the combination in which the dispersion medium forms the above-mentioned fixed two-layer structure, the first dispersion medium 6 and the second dispersion medium 7
Can be appropriately selected from conventionally known dispersion media and used. Examples of such combinations include water-toluene, water-kerosene, and water-xylene. Which is the first dispersion medium 6 and which is the second dispersion medium 7
Can be appropriately selected as needed.
Further, the first dispersion medium 6 is preferably formed in a thinner layer than the second dispersion medium 7, and the use ratio thereof can be appropriately set as needed.

The first and second dispersion media need not be composed of a single dispersion medium, but may be a mixture of two or more dispersion media. For example, there is a case where the second dispersion medium is a mixture of kerosene and carbon tetrachloride with respect to the water of the first dispersion medium.

In the present embodiment, the first dispersion medium 6 is colored by a coloring agent such as a dye or a pigment so as to have a shielding power. The second dispersion medium 7 may be colored or uncolored as necessary, and may or may not have a shielding power. As the dyes and pigments used for coloring, various dyes or pigments that make a contrast with the color of the magnetic particles can be used, and those conventionally used for coloring the dispersion liquid of the magnetic particles of the magnetic panel are appropriately selected. Can be used. Further, conventionally, a thickening agent such as a metal soap, a surfactant, an organic gelling agent, a polymer compound, fine powdered silicic acid, bentonite and the like are blended in the dispersion liquid of the magnetic particles of the magnetic panel. Also in the present embodiment, these compounding agents can be compounded.

As the magnetic particles 5, those conventionally used as magnetic particles of a magnetic panel can be appropriately selected and used, such as black magnetite, γ-hematite,
Oxide magnetic materials such as chromium dioxide and ferrite, iron,
Powders or flakes of metal magnetic materials such as alloys such as cobalt and nickel, or granules of these in order to adjust the size, shape, color tone and the like can be given. The size of the magnetic particles 5 can be any size as required from fine powder to coarse particles, and the shape can be spherical, columnar, massive, or flaky. Further, the magnetic particles 5 can be used in various colorants with a color tone different from the intrinsic color, but with a color tone that makes a contrast with the dispersion medium.
The amount of the magnetic fine particles to be used can be appropriately set as required, but in general, it is suitably 15 parts by weight or more based on 100 parts by weight of the total amount of the first dispersion medium and the second dispersion medium.

In the present embodiment, if necessary,
By applying a surface treatment to the magnetic particles 5 to give an affinity to the second dispersion medium 7, the contrast between the display portion and the non-display portion can be further increased. That is, when the magnetic particles 5 have a strong affinity with the second dispersion medium 7, the writing magnet 17
When the display is formed by adsorbing the magnetic particles 5 on the display surface by scanning, the second dispersion medium 7 is somewhat adsorbed on the magnetic particles 5 due to strong affinity with the magnetic particles. And is accompanied by the magnetic particles 5. The entrained second dispersion medium 7 rushes into the first dispersion medium 6 having a shielding power in the display unit and removes it. At this time, the second dispersion medium 7
Is a dispersion medium having small or no shielding power, the shielding of the magnetic particles 5 in the display portion is suppressed, and the contrast between the magnetic particles in the display portion and the first dispersion medium 6 in the non-display portion is further enhanced. Can be As the surface treatment to be performed on the magnetic particles 5 at this time, from the same treatment as the above-described treatment for imparting affinity to the first dispersion medium 6 on the inner surface of the display surface substrate, according to the type of the second dispersion medium 7 Can be selected appropriately. Further, when the magnetic particles 5 are made of a material having an affinity for the second dispersion medium 7, it is needless to say that it is not always necessary to perform the affinity imparting surface treatment.

As the display surface substrate 1, a transparent or semi-transparent glass plate or various synthetic resin plates as necessary can be used. However, it is preferable that the material is a material having an affinity for the first dispersion medium 6, or if not, it is preferable to perform a process for imparting an affinity to the first dispersion medium 6 on the inner surface. The back substrate 2 does not necessarily need to be transparent or translucent, and may be a glass plate, various synthetic resin plates, or various metal plates.
The thickness of these substrates can be arbitrarily selected as needed. The thicknesses of these substrates do not necessarily have to be the same, and may be changed as necessary, for example, by increasing the thickness of the display substrate 1 and decreasing the thickness of the back substrate 2. be able to. The display surface substrate 1 and the back surface substrate 2 can be colored as required. However, the display surface substrate 1 is colored so as not to lose transparency or translucency.

As the cell constituting member 3, a glass plate,
Known members such as various synthetic resin plates or various metal plates can be used, and the shape of the cell can also take various shapes. The cell constituent member 3 is fixed to the display surface substrate 1 and the back surface substrate 2 so that the sealed dispersion liquid does not leak.

As the microcapsules 8, various known microcapsules can be used other than selecting a material having an affinity for the first dispersion medium 6 as a shell material. The microcapsules 8 are also fixed to the display surface substrate and the back substrate by bonding or the like so that the microcapsules are not damaged.

Further, in the manufacture of the magnetic panel, the display surface substrate 1, the first dispersion medium 6, and the second dispersion medium 7 satisfying the requirements for forming the above-mentioned colored dispersion medium into a fixed two-layer structure are used. A conventional magnetic material is used except that the magnetic particles 5 are made of a material having an affinity for the second dispersion medium 7 or a magnetic particle 5 which has been subjected to an affinity imparting surface treatment with the second dispersion medium 7 if necessary. It can be performed according to the panel manufacturing method.

Hereinafter, an erasing device according to the magnetic panel of the present embodiment will be described. FIG. 3 is an example showing a process of forming a display in the magnetic panel of FIG. The display of the magnetic panel A is performed by moving the magnetic pen 11 provided with the writing magnet 17 in the direction of arrow A along the surface of the display surface substrate 1 and applying a magnetic field to the magnetic pen 11 inside the display surface substrate 1. 5 is adsorbed, and the adsorbed portion produces a contrast with another portion, that is, the first dispersion medium 6 of the non-display portion, and a display is formed. As shown in FIG. 4, partial erasure of the formed display is performed by moving the erasing magnet 14 to which the spacer 13 is fixed along the surface of the display surface substrate 1 in the direction of the arrow B along the surface of the display surface substrate 1. To apply a magnetic field. As a result, the ferromagnetic plate 10 is magnetically induced and magnetized by the erasing magnet 14, and the magnetic particles 5 of the display portion to be erased are arranged in the direction of the magnetic field generated between the erasing magnet 14 and the ferromagnetic plate 10. The display part disappears apparently. The reason is that when the magnetic particles 5 of the display portion are arranged in the direction of the magnetic field generated between the erasing magnet 14 and the ferromagnetic plate 10, the first dispersion medium 6 has an affinity with the inner surface of the display surface substrate 1. This is because the first dispersion medium 6 having the shielding ability readily and easily covers the display portion trace on the inner surface of the display surface substrate 1 and shields the magnetic particles 5 arranged in the direction of the magnetic field. In this magnetic panel A,
For example, dark stains do not remain on the partial erase marks as in the related art, and a color tone equivalent to that of a non-display portion having no display from the beginning can be recovered.

FIG. 5 is an enlarged view of the display unit in the example of FIG. 3 in which the magnetic particles 5 have a surface treatment layer having an affinity for the second dispersion medium 7. In the example of FIG. 5, the magnetic particles 5 adsorbed inside the display surface substrate 1 for forming a display are displayed.
Has a surface treatment layer 15 having an affinity for the second dispersion medium 7, and has a layer 16 of the second dispersion medium 7 adsorbed and entrained due to the affinity of the surface treatment layer 15. I have. The layer 16 of the second dispersion medium 7 excludes the first dispersion medium 6 having a shielding power from around the magnetic particles 5 having the surface treatment layer 15. Therefore, if the second dispersion medium 7 is a dispersion medium having a small or no shielding power, the shielding of the magnetic particles 5 in the display section is suppressed, and the first dispersion of the magnetic particles 5 in the display section and the first dispersion in the non-display section are suppressed. The contrast with the medium 6 is further enhanced.

Further, the display section can be made as shown in FIG. 6 depending on the types of the first and second dispersion media, the size of the magnetic particles, the degree of surface treatment, and the like. Similarly, in the case of FIG. 6, the contrast between the magnetic particles 5 of the display unit and the first dispersion medium 6 of the non-display unit is increased by reducing the shielding power of the second dispersion medium 7.

In the case where the second dispersion medium has a shielding power, the display can be recognized by the color of the second dispersion medium surrounding the magnetic particles instead of the magnetic particles. By appropriately selecting the color of the second dispersion medium, the contrast with the non-display portion can be further enhanced.

Next, FIG. 7 is an example showing a process of forming a display in the magnetic panel of FIG. The display of the magnetic panel A is performed by moving the magnetic pen 11 provided with the writing magnet 17 in the direction of arrow C along the surface of the display surface substrate 1 and applying a magnetic field to the micro pen 11 inside the display surface substrate 1. The magnetic particles 5 are adsorbed on the shell 9 side of the capsule 8, and the adsorbed portion produces contrast between the non-display portion and the first dispersion medium 6, thereby forming a display. As shown in FIG. 8, partial erasing of the display is performed by moving the erasing magnet 14 to which the spacer 13 is fixed along the surface of the display surface substrate 1 in the direction indicated by the arrow along the surface of the display surface substrate 1 to be erased. Let it work. As a result, the ferromagnetic plate 10 is magnetically induced and magnetized by the erasing magnet 14, and the magnetic particles 5 of the display portion to be erased are micro-sized in the direction of the magnetic field generated between the erasing magnet 14 and the ferromagnetic plate 10. It is arranged inside the capsule 8. With this arrangement, the first dispersion medium 6 has an affinity for the inner surface of the microcapsule 8, so that the first dispersion medium 6 having a shielding power readily and easily covers the display portion mark on the inner surface of the microcapsule 8, To shield the magnetic particles 5 arranged in a row. As a result, for example, dark stains, etc., do not remain on the partial erase marks, and the same color tone as that of the non-display portion having no display from the beginning can be recovered.

Furthermore, when the magnetic particles 5, the first dispersion medium 6, and the second dispersion medium 7 are respectively colored differently, a color display is performed according to the mixed state of these colorings.

[0038]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Example 1 To 80 parts by weight of water and 20 parts by weight of titanium oxide white, a pigment dispersant and methylcellulose as a thickener were added and mixed to obtain a white first dispersion medium. Further, 45 parts by weight of kerosene and 55 parts by weight of carbon tetrachloride were mixed to obtain a second dispersion medium. The specific gravity of both the first and second dispersion media was 1.21. Further, 27 parts by weight of Todacolor KN320 (magnetite manufactured by Toda Kogyo Co., Ltd.) and 20% by weight of Gohsenol GM14 (polyvinyl alcohol manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
15 parts by weight of the aqueous solution was kneaded with three rolls, dried and pulverized to obtain 20 parts by weight of black magnetic particles of 250 to 325 ^# . The magnetic particles were uniformly dispersed in the second dispersion medium to obtain a dispersion liquid.

The first dispersion medium, the magnetic particles and the second dispersion medium are filled in an aluminum honeycomb (cell size: 3 mm, thickness: 3 mm) adhered to a display substrate of a transparent vinyl chloride sheet having a thickness of 0.15 mm. A magnetic panel was formed by bonding and sealing the back substrate of a transparent vinyl chloride sheet having a thickness of 0.15 mm and sealing the ends of the display surface substrate and the back substrate. Using this magnetic panel, a silicon steel plate having a thickness of 0.35 mm was arranged and bonded to the back surface, and a transparent acrylic plate having a thickness of 0.1 mm was provided on the front surface. ,
A display is formed using a display magnet having a magnetic force of 1500 G and a size of 1.5 mmφ.
A magnetic force of 1700 G with a 10 mm spacer fixed,
The display was partially erased using an erasing magnet having a size of 12 × 40 × 8 mm. As a result, the formed display showed high-contrast contrast. In addition, when the trace of partial erasure of the display was visually observed, no stain remained, and the color tone was the same as that of the non-display portion.

Example 2 A magnetic panel was prepared and a display was formed in the same manner as in Example 1 except that the inside of the acrylic plate serving as the display surface was subjected to plasma treatment in advance, and a display was formed. Was partially erased. When the formed display was evaluated in the same manner as in Example 1, the contrast became clearer than in Example 1. In addition, when the trace of partial erasure of the display was evaluated in the same manner as in Example 1, similar to the case of Example 1,
No stain remained, and the color tone was equivalent to that of the non-display portion.

[0041]

According to the present invention, even when partial erasure of a display is performed, the partial erasure trace can be restored to the same color tone as that of the non-display portion without leaving stains on the partial erasure trace of the display. Is provided. Further, in the magnetic panel of the present invention, the contrast between the display portion and the non-display portion can be further increased by considering the affinity between the magnetic particles and the dispersion medium used, especially the second dispersion medium.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a cross section of one embodiment of a magnetic panel of the present invention.

FIG. 2 is a schematic view illustrating a cross section of another embodiment of the magnetic panel of the present invention.

FIG. 3 is a schematic view illustrating a display forming process in one embodiment of the magnetic panel of the present invention.

FIG. 4 is a schematic view illustrating a partial erasing process in one embodiment of the magnetic panel of the present invention.

FIG. 5 is an enlarged view schematically showing a display section of the magnetic panel of the present invention.

FIG. 6 is an enlarged view schematically showing another display unit of the magnetic panel of the present invention.

FIG. 7 is a schematic view illustrating a display forming process in another embodiment of the magnetic panel of the present invention.

FIG. 8 is a schematic view illustrating a partial erasing process in another embodiment of the magnetic panel of the present invention.

FIG. 9 is a schematic diagram illustrating a display forming process in the magnetic panel of the invention.

FIG. 10 is a schematic view showing a partial erasing process in the magnetic panel of the invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display surface substrate 2 Back surface substrate 3 Cell constituent member 4 Cell 5 Magnetic particle 6 First dispersion medium 7 Second dispersion medium 8 Microcapsule 9 Microcapsule shell 10 Ferromagnetic plate 11 Magnetic pen 12 Dispersion medium 13 Spacer 14 For erasing Magnet 15 Surface treatment layer 16 Second dispersion medium layer 17 Writing magnet A Magnetic panel

Claims (7)

[Claims] 1. A dispersing medium comprising a first dispersing medium and a second dispersing medium that are not substantially mixed with each other, wherein the first dispersing medium is formed in a thinner layer than the second dispersing medium. A magnetophoretic display panel disposed on a display surface side of the magnetophoretic display panel to form a shielding layer, and wherein the second dispersion medium is disposed on a portion other than the display surface side of the magnetophoretic display panel and disperses magnetic particles. 2. The magnetophoretic display panel according to claim 1, wherein the first dispersion medium and the second dispersion medium have substantially the same specific gravity. 3. The magnetophoretic display panel according to claim 1, wherein the first dispersion medium is colored with a shielding property. 4. The magnetophoretic display panel according to claim 1, wherein the second dispersion medium and the first dispersion medium are colored in different colors. 5. The magnetic particle according to claim 1, wherein the magnetic particles have an affinity for the second dispersion medium or have been subjected to a surface treatment having an affinity for the second dispersion medium. Magnetophoretic display panel. 6. The method according to claim 1, wherein the first dispersion medium has a stronger affinity for the display surface of the magnetophoretic display panel than the second dispersion medium. Magnetophoretic display panel. 7. The magnetic recording medium according to claim 1, wherein the second dispersion medium has a higher affinity than the first dispersion medium except for the display surface side of the magnetophoretic display panel. The magnetophoretic display panel according to the above.